blob: 8a1c4a9dba0dfc2ec96ba8926efff61b2ed0f101 [file] [log] [blame]
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "DisplayEventReceiver"
//#define LOG_NDEBUG 0
#include "JNIHelp.h"
#include <android_runtime/AndroidRuntime.h>
#include <utils/Log.h>
#include <utils/Looper.h>
#include <utils/threads.h>
#include <gui/DisplayEventReceiver.h>
#include "android_os_MessageQueue.h"
namespace android {
// Number of events to read at a time from the DisplayEventReceiver pipe.
// The value should be large enough that we can quickly drain the pipe
// using just a few large reads.
static const size_t EVENT_BUFFER_SIZE = 100;
static struct {
jclass clazz;
jmethodID dispatchVsync;
} gDisplayEventReceiverClassInfo;
class NativeDisplayEventReceiver : public RefBase {
public:
NativeDisplayEventReceiver(JNIEnv* env,
jobject receiverObj, const sp<Looper>& looper);
status_t initialize();
status_t scheduleVsync();
static int handleReceiveCallback(int receiveFd, int events, void* data);
protected:
virtual ~NativeDisplayEventReceiver();
private:
jobject mReceiverObjGlobal;
sp<Looper> mLooper;
DisplayEventReceiver mReceiver;
bool mWaitingForVsync;
};
NativeDisplayEventReceiver::NativeDisplayEventReceiver(JNIEnv* env,
jobject receiverObj, const sp<Looper>& looper) :
mReceiverObjGlobal(env->NewGlobalRef(receiverObj)),
mLooper(looper), mWaitingForVsync(false) {
ALOGV("receiver %p ~ Initializing input event receiver.", this);
}
NativeDisplayEventReceiver::~NativeDisplayEventReceiver() {
ALOGV("receiver %p ~ Disposing display event receiver.", this);
if (!mReceiver.initCheck()) {
mLooper->removeFd(mReceiver.getFd());
}
JNIEnv* env = AndroidRuntime::getJNIEnv();
env->DeleteGlobalRef(mReceiverObjGlobal);
}
status_t NativeDisplayEventReceiver::initialize() {
status_t result = mReceiver.initCheck();
if (result) {
ALOGW("Failed to initialize display event receiver, status=%d", result);
return result;
}
int rc = mLooper->addFd(mReceiver.getFd(), 0, ALOOPER_EVENT_INPUT,
handleReceiveCallback, this);
if (rc < 0) {
return UNKNOWN_ERROR;
}
return OK;
}
status_t NativeDisplayEventReceiver::scheduleVsync() {
if (!mWaitingForVsync) {
ALOGV("receiver %p ~ Scheduling vsync.", this);
// Drain all pending events.
DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE];
ssize_t n;
while ((n = mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) {
ALOGV("receiver %p ~ Drained %d events.", this, int(n));
}
if (n < 0) {
ALOGW("Failed to drain events from display event receiver, status=%d", status_t(n));
return status_t(n);
}
status_t status = mReceiver.requestNextVsync();
if (status) {
ALOGW("Failed to request next vsync, status=%d", status);
return status;
}
mWaitingForVsync = true;
}
return OK;
}
int NativeDisplayEventReceiver::handleReceiveCallback(int receiveFd, int events, void* data) {
sp<NativeDisplayEventReceiver> r = static_cast<NativeDisplayEventReceiver*>(data);
if (events & (ALOOPER_EVENT_ERROR | ALOOPER_EVENT_HANGUP)) {
ALOGE("Display event receiver pipe was closed or an error occurred. "
"events=0x%x", events);
return 0; // remove the callback
}
if (!(events & ALOOPER_EVENT_INPUT)) {
ALOGW("Received spurious callback for unhandled poll event. "
"events=0x%x", events);
return 1; // keep the callback
}
// Drain all pending events, keep the last vsync.
nsecs_t vsyncTimestamp = -1;
uint32_t vsyncCount = 0;
DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE];
ssize_t n;
while ((n = r->mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) {
ALOGV("receiver %p ~ Read %d events.", data, int(n));
while (n-- > 0) {
if (buf[n].header.type == DisplayEventReceiver::DISPLAY_EVENT_VSYNC) {
vsyncTimestamp = buf[n].header.timestamp;
vsyncCount = buf[n].vsync.count;
break; // stop at last vsync in the buffer
}
}
}
if (vsyncTimestamp < 0) {
ALOGV("receiver %p ~ Woke up but there was no vsync pulse!", data);
return 1; // keep the callback, did not obtain a vsync pulse
}
ALOGV("receiver %p ~ Vsync pulse: timestamp=%lld, count=%d",
data, vsyncTimestamp, vsyncCount);
r->mWaitingForVsync = false;
JNIEnv* env = AndroidRuntime::getJNIEnv();
ALOGV("receiver %p ~ Invoking vsync handler.", data);
env->CallVoidMethod(r->mReceiverObjGlobal,
gDisplayEventReceiverClassInfo.dispatchVsync, vsyncTimestamp, vsyncCount);
ALOGV("receiver %p ~ Returned from vsync handler.", data);
if (env->ExceptionCheck()) {
ALOGE("An exception occurred while dispatching a vsync event.");
LOGE_EX(env);
env->ExceptionClear();
}
return 1; // keep the callback
}
static jint nativeInit(JNIEnv* env, jclass clazz, jobject receiverObj,
jobject messageQueueObj) {
sp<Looper> looper = android_os_MessageQueue_getLooper(env, messageQueueObj);
if (looper == NULL) {
jniThrowRuntimeException(env, "MessageQueue is not initialized.");
return 0;
}
sp<NativeDisplayEventReceiver> receiver = new NativeDisplayEventReceiver(env,
receiverObj, looper);
status_t status = receiver->initialize();
if (status) {
String8 message;
message.appendFormat("Failed to initialize display event receiver. status=%d", status);
jniThrowRuntimeException(env, message.string());
return 0;
}
receiver->incStrong(gDisplayEventReceiverClassInfo.clazz); // retain a reference for the object
return reinterpret_cast<jint>(receiver.get());
}
static void nativeDispose(JNIEnv* env, jclass clazz, jint receiverPtr) {
sp<NativeDisplayEventReceiver> receiver =
reinterpret_cast<NativeDisplayEventReceiver*>(receiverPtr);
receiver->decStrong(gDisplayEventReceiverClassInfo.clazz); // drop reference held by the object
}
static void nativeScheduleVsync(JNIEnv* env, jclass clazz, jint receiverPtr) {
sp<NativeDisplayEventReceiver> receiver =
reinterpret_cast<NativeDisplayEventReceiver*>(receiverPtr);
status_t status = receiver->scheduleVsync();
if (status) {
String8 message;
message.appendFormat("Failed to schedule next vertical sync pulse. status=%d", status);
jniThrowRuntimeException(env, message.string());
}
}
static JNINativeMethod gMethods[] = {
/* name, signature, funcPtr */
{ "nativeInit",
"(Landroid/view/DisplayEventReceiver;Landroid/os/MessageQueue;)I",
(void*)nativeInit },
{ "nativeDispose",
"(I)V",
(void*)nativeDispose },
{ "nativeScheduleVsync", "(I)V",
(void*)nativeScheduleVsync }
};
#define FIND_CLASS(var, className) \
var = env->FindClass(className); \
LOG_FATAL_IF(! var, "Unable to find class " className); \
var = jclass(env->NewGlobalRef(var));
#define GET_METHOD_ID(var, clazz, methodName, methodDescriptor) \
var = env->GetMethodID(clazz, methodName, methodDescriptor); \
LOG_FATAL_IF(! var, "Unable to find method " methodName);
int register_android_view_DisplayEventReceiver(JNIEnv* env) {
int res = jniRegisterNativeMethods(env, "android/view/DisplayEventReceiver",
gMethods, NELEM(gMethods));
LOG_FATAL_IF(res < 0, "Unable to register native methods.");
FIND_CLASS(gDisplayEventReceiverClassInfo.clazz, "android/view/DisplayEventReceiver");
GET_METHOD_ID(gDisplayEventReceiverClassInfo.dispatchVsync,
gDisplayEventReceiverClassInfo.clazz,
"dispatchVsync", "(JI)V");
return 0;
}
} // namespace android